Time
Introduction: It has long been a spirited topic of debate, in science and philosophy, what “is” time? There are widely uncertain views and opinions about its meaning, thus making it difficult to provide a unified definition of time. Scientists believe that time is a quality that can be measured, and utilized mathematically to derive other qualities. However, scholars on the other hand believe that time cannot be measured and/or be used as a measuring device. The Oxford English Dictionary defines time as “the indefinite continued progress of existence and events in the past, present, and future, regarded as a whole.” Another dictionary source (www.dictionary.com) states “time is a non-spatial continuum in which events occur in apparently irreversible succession from the past through the present to the future.” The Latin word for time, Tempus, came form the Greek root, temnein meaning, “to cut;” same root for atomos, meaning “invisible,” thus portentous in pointing out the complexity behind the true definition of time. According to this Greek definition, time is the invisible non-spatial continuum with a flowing duration of measurement and/or substance. What that means is unclear to me. Fundamentals: Time: "A non-spatial continuum in which events occur in apparently irreversible succession from the past through the present to the future." Second: A mode of measuring intervals of time, such as a mintue, an hour, and a day. 60 seconds = 1 minute 3 600 seconds = 1 hour 86.4 kiloseconds (86 400 seconds) = 1 day (in the SI sense) Space: The standard “space” interval called a “meter,” is defined as the distance traveled by light in a vacuum during a "time interval of 1/299792458 of a second." Special Relativity Theory: This theory proposed, the concept of inertia in time intervals on a location where gravity is ignored. If the first definition of time is too confusing try these: - An time interval separating two points. Such as the number of seconds it takes for one to travel a certain distance. - A number, as of years, days, or minutes, representing such an interval. Time in Physics: Listed as a fundamental quantity, time in physics is treated as a question of geometry. One can treat it as a dimension, with geometric qualities. Time, in conjunction with other fundamental quantities, can be used mathematically, in order to derive other concepts such as motion, energy, and fields. The current definition of time, the definition used by scientists is the following: “The standard time interval (called conventional second, or simply second) is defined as 9 192 631 770 oscillations of a hyperfine transition in the 133 caesium atom.”The issue with this definition is that one cannot derive what time “is” and how it functions by comprehending this scientific denotation. Space in Physics: In physics space alongside with time is considered one of the few fundamental quantities, being the two most simplest fundamental knowledge scientists know of today. Similar to the evaluation of time, space is defined and acknowledged by measurement. The standard “space” interval called a “meter,” is defined as "the distance traveled by light in a vacuum during a time interval of 1/299792458 of a second", the standard time interval “second” defined as "9 192 631 770 oscillations of a hyperfine transition in the 133 caesium atom." These two fundamental qualities in physics when entwined create what is known as “space-time,” a huge role-playing factor in the Einstein’s famous “special relativity theory.” The History of Time: In 1905 Albert Einstein proposed his theory called special relativity. This theory proposed the concept of inertia in time intervals on a location where gravity is ignored. According to this theory space and time are entwined so that the speed of light is constant. The questioning and disbeliefe of this relativity theory brought Einstein to the realization of his famous equation E=mc^2. However before Albert Einstein came into the picture with all of his wierd ideas and thories wich no one listened to, the first methods of keeping track of time were prevalent with the Eygptions. The Egyptions were the first to tell time using a clock. By 2100 BC they have invented a means to divide the day into 24 hours. They created what is known as the sundial or shadow clock. The time is measured and or tolled by the positioning of the shadow of some object on which the sun's rays fall. The sundial has a cirular base with divisions inscribed onto it, dividing the time of day into 24 hours, and the clock is set east-west. Putting Time to the Test: In physics time is used in conjunctions with alot of concepts, such as velocity, distance, and displacment per specific intervals. Fundamentals: -"Velocity v = Delta(S)speed / Delta(T)time" -"Average speed V = 1/2(v) subscript f(final velocity)" Problems dealing with time in Physics / With real life examples: Problem 1 1)If a turtle's accelerates uniformaly for 4.0 seconds attaining a maximum speed of 10. meters per second, the average speed would be? 1)5.0 m/s^2 2)7.5 m/s^2 3)13 m/s^2 4)20 m/s^2 The answer is choice #1. The turle's average speed would be 5.o m/s^2. The calculations are the following: average speed = 1/2(vf) = 1/2(10. m/s) = 5.0 m/s Problem 2 2) It takes a car 0.20 hours to travel a distance of 12 kilometers, what is the km/h? 1) 20. km/h 2) 40. km/h 3) 60. km/h 4)80. km/h The answer is choice #3. The car travles 60 kilometers per hour, the calculations are as follow: Velocity = speed/time = 12.km/0.20.h = 60.km/h Problem 3 3) A bird uniformly accelerates from rest to a speed of 25. meters per second in 10 seconds, what is the accelaration? 1) .5 m/s^2 2) 1 m/s^2 3) 2 m/s^2 4) 2.5 m/s^2 The answer choice is #4. The bird accelerates 2.5 meters ever second for ten straight seconds. The calculations follow: Acceleration = (25.-0)m/s/10s = 2.5 m/s^2 References: These references were utilized to create this wiki page (1)dictionary.com (Time, second, space) (2)m-w.com (Time, spacetime, speed) (3)answers (history of the clock / time) (4)wiki (specificaly special relativity) (5)stanford research (specificaly special relativity, and the second) (6)Ninth year Mathematics (By, Dressler Isidore, New York, Amsco School Publication 315 Hudson street New York N.Y. 10013,1988) Resources (1)Barron's Regents Exams and Answers (Physics)(Lazar, Miriam A. Barron's Review Course Series Let's Review: Physics: The Physical Setting. 2 ed. New York: Barron's Educational Series, 1999.) (2)Glencoe Physics Principles and Problems (By: Paul W. Zitzewits, Ph.D, McGraw-Hill 8787 Orion Place, 43240, 1999) (3)Barron's Review Course Series Lets review Physics (Miriam A. Barron's Review Course Series Let's Review: Physics: The Physical Setting. 3 ed. New York: Barron's Educational Series, 2005.) (4)Time / space / special relativity (5)Albert Einstien (6)The little Oxford Dictionary (Edited by Maurice Waite, sixth edition, 1986)